Plastic container with double lock lid

ABSTRACT

An all plastic container comprising the combination of injection molded pail and lid. The lid initially locks onto the container at upper and lower undercuts and seals thereto by virtue of an inverted U-shaped peripheral section. A tear line is formed in the lid skirt to facilitate removal of the lower lock. The upper lock is segmented so as to make removal of the lid easier once the lower lock is removed. Indicia on the lid shows where the gaps in the lock segments are located. The lower lock may also be segmented to provide drainage for overfill which comes out of the pail when the lid is first applied.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of the co-pending U.S. patent application Ser. No. 11/880,524 filed Jul. 23, 2007.

FIELD OF THE INVENTION

This invention relates to plastic containers of the type comprising a pail and a lid which sealingly fits onto the pail without the need for a gasket and further wherein the container combination has two locks which hold the lid onto the pail and a circumferential tear line which allows one of the locks to be removed.

BACKGROUND OF THE INVENTION

Plastic containers comprising the combination of an open top pail and a lock-on lid or closure are well known and have been in commercial use for shipping and merchandising various products in the United States for many years. The word “lock”, as used in this product area, refers to an undercut-based snap fit between the pail and lid which inhibits removal of the lid, sometimes strongly enough to require the use of a tool or physical alteration of the lid, to achieve removal. Some containers have largely supplanted metal containers in many areas including adhesives, food products, paint, wallboard paste, spackling, driveway sealant and other products. The pail and lid are typically injection molded of a suitable polymeric material such as high density polyethylene or polypropylene. The seal between the pail and the lid can be achieved by providing a compressible O-ring gasket or by molding a notch in the top of the pail rim flange and providing a corresponding bead in the under side of the inverted U-shaped channel of the lid which receives the rim bead of the pail. This later structure is described in the published U.S. Application US 2002/0148846. Still another seal structure is illustrated in the expired patent to Richard Landis, U.S. Pat. No. 4,418,833.

SUMMARY OF THE INVENTION

The present invention provides a container comprising the combination of an open top pail and a lid, both preferably made of injection molded plastic such as polyethylene or polypropylene, wherein a good seal is provided between the pail and the lid without the need for either a gasket or special features such as rim beads and notches in the top of the pail.

In general, this is achieved by providing a pail with a flangeless top rim, and a lid having a narrow inverted U-shaped peripheral channel defined by an inner annular ring which is reinforced by radial ribs.

In addition, and in accordance with a preferred embodiment of the invention, multiple undercut-type locks are provided for securing the lid to the pail wherein said multiple locks comprise an upper lock comprising a continuous bead on the outer wall of the container immediately below the top edge and a plurality of widely circumferentially spaced locking segments on the inside surface of the inverted U-shaped channel formed by the lid to provide widely spaced, discrete undercuts which receive the pail sidewall bead and lock thereto. The second or lower of the two locks is provided lower down on the container sidewall at or near the bottom of the outer skirt of the lid. This second lower lock may be circumferentially discontinuous, providing gaps which allow overfill material to drain.

The lower lock is made removable by forming a circumferentially extending weakened area or “tear line” in the lid skirt such that the portion of the skirt below the weakened area can be torn away leaving only the upper lock in place. This manipulation is typically carried out by the end user. The tear line is located well below the upper lock, thereby providing, after removal of the lower skirt, enough remaining skirt to afford a good hand-hold for subsequent removal of the lid.

In the preferred form, the upper lock is provided in two, three or four discrete and circumferentially spaced areas and indicia are carried on the top surface of the lid to show where the locking segments are located and to direct the user to apply a lifting force in that area to remove the lid from the container once the tear band has been pulled away. In the illustrated embodiment, there are three such indicia in the forms of arrows with the legend “LIFT” molded into the top deck of the lid thereby to eliminate the need for a printing function or the application of a decal. However, both of these alternatives as well as other alternatives, while not preferred, are useable in accordance with the more detailed aspects of the present invention.

Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

FIG. 1 is a perspective view of an all plastic injection molded container comprising a pail and lid embodying the invention;

FIG. 1A is a perspective view of the FIG. 1 container with the lid removed;

FIG. 2 is a plan view of the inside surface of the lid from the combination of FIG. 1;

FIG. 3 is a plan view of the outside or top surface of the lid of FIG. 2;

FIG. 4 is a side view in section of an enlarged portion of the lid and pail showing how the upper and lower locks are formed;

FIG. 5 is a side view in section showing the upper and lower locks engaged; and

FIG. 6 is a composite of side views in section showing how containers stack on top of one another.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

Referring to the Figures there is shown an all plastic container 10 comprising the combination of a tapered cylindrical plastic pail 12 and an injection molded lock-on plastic lid 14. In this illustrative embodiment the pail 12 and lid 14 are both injection molded of high density polyethylene, but other materials such as polypropylene may be used as alternatives.

The pail 12, which in this instance is a 3½ gallon pail but can be made in a variety of other larger and smaller sizes, comprises a tapered cylindrical side wall 16 extending upwardly to an enlarged diameter collar 18 which is integral with, but is spaced outwardly from, the wall 16 by ribs 32 and lies below the upper rim portion 26 as best shown in FIG. 1A. The collar 18 runs circumferentially around the entirety of the pail 12 and has diametrically opposite ear portions 20 which receive a wire bail 22 having a ferrule type plastic handle 24 mounted thereon.

As shown in FIG. 1A the upper rim portion 26 of the open top container 12 is featureless; i.e., it has no notches, flanges or beads at the upper end. However, approximately ½ to ¾″ below the upper rim portion 26 and on the inside surface of the side wall 16 is a bump 27 which protrudes radially inwardly about 0.010″ from the surrounding surface to create a “pinch seal” with the closure 14 as hereinafter described. On the outer sidewall 16 about 1 inch below the rim is a bead 28 which is circumferentially continuous around the pail 12 and forms part of an upper lock to be described. Approximately 4 inches below the bead 28 is a second radially outwardly extending bead 30 which is preferably notched at six or eight evenly spaced locations and is integral and contiguous with the radially outstanding collar 18. Reinforcing ribs 32 are provided at circumferential intervals of about 1⅛″ around the pail. Additional ribs 33 run vertically between the outwardly flared wall below the bead 28 and the top of the bead 30 to stiffen the sidewall 16 and prevent deflection under stacking loads. Ribs 33 are integral with the outer sidewall, run vertically and are spaced, for example, at 30° intervals around the pals. Ribs 33 are approximately 4 inches long.

Looking at the lid 14, it comprises an inverted U-shaped peripheral channel portion 34 defining a downwardly opening and radially narrow, internal channel 36 which snugly and sealingly receives the top rim portion 26 of the pail 12 therein. The inverted U-shaped channel peripheral portion 34 comprises an outer wall 38 and a downwardly extending annular inner wall 40 having circumferentially spaced reinforcing ribs 42 as shown in FIGS. 2 and 4. The outer surface of the lid has a recessed deck 44 with the tapered lead surface 46 from the peripheral channel portion 34 to make it easier to stack one of the containers on top of another of like size and design.

In accordance with the invention, an upper lock comprises the combination of the bead 28 on the pail side wall 16 and three evenly circumferentially spaced locking segments 48 forming undercuts 50 on the inside surface of the outer skirt 52 of the lid. When the lid 14 is firmly attached to and seated on the pail 12 the bead 28 fits within the undercuts 50 of the three locking segments 48 to hold the lid 14 on the pail 12.

The lid 14 is originally molded with a long skirt including the upper wall 30 and a lower portion 52 separated by a circumferential teat line 56 which is made thin and weak enough to allow the lower portion 52 to be torn off. A starter tab 60 is provided to facilitate tearing. Note that the tear line 56 is about 1 to 2 inches below the lock bead 28 which fits into the undercut notch 50 in the inner surface of the lid's upper skirt. This gives a large handhold to grasp the outwardly flared upper skirt above the tear line 56 after the lower skirt 52 is removed as shown in the top part of FIG. 6. At the bottom of the lower skirt 52 is another inwardly-extending flange or undercut 54 which snaps under the outer edge of the bead 30 to form the lower lock. Gaps 53 may be molded into the undercut 54 at regular intervals to drain any overfill that might be forced out of the pail when the lid 14 is first applied. This prevents material from accumulating between the pail sidewall 16 near feature 30 and the lower lid skirt; a potentially odor-causing condition if the fill material is a food product subject to spoiling.

Further accordance with the invention, indicia 58 comprising the combination of outwardly directed arrows and the legend “LIFT” are molded into the top surface of the deck 44 to indicate exactly where the locking segments 48 are located such that a user of the pail may apply a lifting force in this area after the removal of the lower skirt 52 has been achieved as hereinafter described. Similar equivalent legends may be used.

The lower skirt portion of the lid 14 comprises the depending skirt 52 terminating an undercut 54 which fits over and receives the bead 30 on the lower locking collar portion 18 or the pail side wall 16 when the lid 14 is placed on pail 12 and firmly seated. However, a circumferentially extending weakened area provided by a notch 56 allows the lower portion of the skirt 52 to be torn away. A starter tab 60 is provided as shown in FIG. 1A in a cut-out area 62 for the purpose of facilitating the removal of the tear band formed by the skirt 52 so as to eliminate the lower lock 30, 54.

In operation, the pail 12 and lid 14 are typically injection molded at a suitable plant site. Once they are shipped to the customer, the container 10 is filled with product (not shown) and the lid 14 is seated on the container 12 such that the upper rim portion 26 of the container side wall extends fully and contactingly into the channel 36 and is sealed by the pinch seal at bump 27. There is a contact seal on both sides of the sidewall 16. The upper lock 28, 50 snaps into place and the lower lock 30, 54 also snaps into place to securely hold the sealed lid 14 on the container 12. Similar containers 10 can be stacked and shipped in the product filled condition without fear of leakage or the ingestion of unwanted air into the interior of the container 10.

When the user is ready to gain access to the product, the starter tab 60 is broken away from the lid portion 52 and the lower skirt 52 is removed. This eliminates the lower lock 30, 54 and also provides evidence that the container 10 has been opened. Once the lower skirt 52 and the lower lock 30, 54, have been removed, the only lock holding the lid 14 to the pail 12 is the segmented upper lock 28, 50. This lock is relatively easily overcome without the use of tools by lifting the revealed edge of the lid 14 immediately adjacent the indicia arrows 58. The plastic pail and lid combination is sufficiently flexible to permit the lid rim channel sidewall 38 below the lock 28 to be flexed outwardly and this overcomes the lock and permits the lid 14 to be removed from the pail 12. It also permits the lid 14 to be relocated and relocked onto the pail 12 using the three 120° spaced locks 28, 50. An audible “snap” occurs when the lid 14 is fully re-seated, telling the user that a good seal has been achieved.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. 

1. A plastic container of the type including an open top pail and a lid which sealingly fits on to the pail wherein the pail wherein the combination comprises: a pail with a sidewall and a top rim; the lid comprising an inverted U-shaped peripheral channel portion integral with a central deck portion and sized to sealingly receive the pail rim; the lid further comprising an outer skirt with a circumferential tear line dividing the skirt into the upper and lower portions; an upper lock, between the pail and lid well above the tear line; and a lower lock between the pail and lid below the tear line; at least the upper lock being circumferentially segmented.
 2. A plastic container of the type described in claim 1 further including indicia carried on the top surface of the deck lid and indicating gaps between segments of the upper lock.
 3. A plastic container of the type described in claim 1 wherein the lower lock is segmented to provide drains.
 4. A plastic container of the type described in claim 1 wherein the inner surface of the pail sidewall has a circumferentially continuous bump formed therein to provide a seal with the lid.
 5. A plastic container of the type described in claim 4 wherein the lid has formed as part of the channel portion an inner wall which seals against the bump on the container inner sidewall surface.
 6. A plastic container combination of the type described in claim 1 wherein the pail and lid are formed of polyethylene.
 7. A plastic container as described in claim 1 further including a plurality of radical reinforcing ribs molded into the underside of the lid and extending to and integrally with the annular inner ring.
 8. A plastic container as defined in claim 1 wherein the upper and lower locks include undercuts on the pail and a plurality of circumferentially spaced vertical ribs are formed on and integral with the pail sidewall between the upper and lower undercuts.
 9. An all plastic container comprising: a solid plastic pail having a side wall terminating in an annular top rim; a first annular locking bead formed integrally and externally of said side wall below said rim; a second annular locking bead formed integrally and externally on said side wall below said first bead and flared outwardly from said side wall; a solid plastic lid comprising a central deck and, integral therewith, an annular peripheral portion forming an inverted U-shaped annular channel which is sized to sealingly receive therein said top rim; said lid further comprising an annular skirt portion integrally depending from said peripheral portion and radially spaced outwardly from said pail side wall when said lid is placed on said pail; an upper locking structure formed integrally with said lid within said channel and coacting with said first annular bead to form an upper lock having circumferentially spaced discontinuities; and a lower locking structure formed on said skirt portion and coacting with said second annular locking bead to form an annular lock between said lid and said pail; and a tear groove formed in said lid between the upper and lower locking structures to permit selective removal of the lower portion of said skirt portions; said tear groove being spaced for enough below the upper lock so as to leave sufficient skirt after tearing to allow the remaining skirt to be grasped for removal.
 10. The combination defined in claim 9 further comprising indicia carried on the top surface of the lid indicating the locations of said discontinuities.
 11. The combination defined in claim 9 wherein said lid and pail are made of solid, high-density polyethylene.
 12. A container as defined in claim 9 wherein the pail has a circumferential bump formed on the inner sidewall surface to provide a pinch seal with the lid channel when the lid is on the pail.
 13. A solid plastic pail comprising: a sidewall terminating in a top rim; an upper bead below the rim on the outer sidewall surface; a lower bead farther below the rim on the outer sidewall surface and spaced farther outwardly from said sidewall than the upper bead; and a plurality of vertical ribs formed integrally with said outer sidewall and extending substantially between the upper and lower beads.
 14. A pail as defined in claim 13 wherein an annular seal bump is formed on the inner sidewall surface below the rim.
 15. A solid plastic closure for a plastic pail comprising: a deck; an annular peripheral structure defining an inverted U-shaped channel; an outer skirt formed as part of said structure; a segmented upper undercut in said skirt; a segmented lower undercut in said skirt; and a tear line between the upper and lower undercuts. 